Grid structure with waved strips having apexes with enlarged sections formed therein

ABSTRACT

A flat or annularly configured grid structure comprising nonplanar or waved strips which are formed to include generally Vshaped portions. Adjacent ones of the generally V-shaped portions have their pointed apexes on opposite sides of the central plane of the strip, and the apexes have sections substantially enlarged longitudinally of the strip for increasing the strength of the strip and facilitating connection of the strip to laterally adjacent structure, such as by welding.

United States Patent [191 Rich Nov. 27, 1973 GRID STRUCTURE WITH WAVED STRIPS HAVING APEXES WITH ENLARGED SECTIONS FORMED THEREIN [75] Inventor: John P. Rich, Nashua, NH.

[73] Assignee: Improved Machinery, Inc., Nashua,

[22] Filed: Sept. 15, 1972 [21] Appl. No.: 289,333

[52] U.S. Cl. 161/68, 29/121 R, 113/116 2, 156/207, 161/69, 161/134, 162/357,

[51] Int. Cl. B32b 3/28, BOld 33/06, D211 l/60 [58] Field of Search 162/357, 372; 113/116 A, 116 Z; 161/134, 68,133, 69;

[56] References Cited UNITED STATES PATENTS 3,158,527 11/1964 Faccin et a1. 156/207 X 3,281,307 10/1966 Moeller et a1. 161/68 3,105,043 9/1963 Rich et a1. 210/402 3,590,453 6/1971 Bryand 210/402 X FOREIGN PATENTS OR APPLICATIONS 597,801 2/1948 Great Britain 161/134 Primary Examiner-S. Leon Bashore Assistant Examiner-Richard H. Tushin Attorney-David W. Tibbott et al.

[5 7] ABSTRACT A flat or annularly configured grid structure comprising non-planar or waved strips which are formed to include generally V-shaped portions. Adjacent ones of the generally V-shaped portions have their pointed apexes on opposite sides of the central plane of the strip, and the apexes have sections substantially enlarged longitudinally of the strip for increasing the strength of the strip and facilitating connection of the strip to laterally adjacent structure, such as by weldmg.

20 Claims, 3 Drawing Figures GRID STRUCTURE WITH 'WAVED STRIPS HAVING APEXES WITH ENLARGED SECTIONS FORMED THEREIN The present invention relates to honeycomb or grid structures such as, by way of specific example only, the annular honeycomb drums employed by the pulp and paper making industry.

Conventionally, as described in US. Pat. No. 3,105,043 assigned to the assignee of the present invention, grid structures of this general type have been constructed from non-planar or waved strips comprising alternate, straight and generally diagonal segments cooperative to cause the strips to include portions of generally truncated triangular configuration. However, when a waved strip of this conventional construction is employed in a conventional annular grid structure, the resultant grid structure is believed to possess only relatively low stiffness when subjected to bending or tension forces acting laterally or cross-wise of the strip.

It is believed that a substantial increase in this stiffness would be obtained in the event that the waved stripscould be constructed to include portions of generally V-shaped construction. -However, the waved strips must, of course, be laterally connected at spaced locations throughout their lengths to form a grid struture; and such connections are normally being made by a welding tool or the like inserted intemaly of their composite portions. Hence, as the relatively sharp or pointed apexes of entirely V-shaped portions would undesirably restrict the access of a welding tool internally of the portions, such construction would undesirably complicate the necessary connections of the waved strips. Also, in the event that the waved strips were formed of entirely V-shaped portions, buckling of the strips under compressive loads might occur when the strips were employed in grid structures including larger openings.

An object of the present invention is to provide a new and improved grid structure which is of substantially increased strength and stiffness and also capable of being readily and simply constructed, such as by weldmg.

Another object of the invention is to provide a new and improved grid structure of the type set forth which is particularly constructed and arranged to include generally V-shaped portions.

Another object is to provide new and improved nonplanar or waved srip means particularly constructed and arranged to, when connected into a grid structure, provide the structure with substantially increased strength and stiffness.

Another object is to provide new and improved nonplanar or waved strip means which, although including generally V-shaped portions, is readily and simply connectible into a grid structure, such as by welding.

Another object is to provide new and improved nonplanar or waved strip means particularly constructed and arranged to avoid buckling under compressive loads, even when incorporated in a grid structure having openings of large size.

Other objects and advantages of the invention will be apparent from the following description taken in connection with the accompanying drawings wherein, as will be understood, the preferred form of the invention has been given by way of illustration only.

In accordance with the present invention, a grid structure may comprise waved strip means including generally V-shaped portions, and the apexes of such generally V-shaped portions of the waved strip means comprising sections of greater widths than other sections thereof.

Referring to the drawings:

FIG. 1 is a partially broken-away, elevational view of an annular grid structure embodying the invention;

FIG. 2 is an enlarged, fragmentary, perspective view illustrating the non-planar or waved strip means of the annular grid structure of FIG. 1; and

FIG. 3 is a fragmentary elevational view showing such non-planar or waved strip means in conjunction with a conventional welding tool which is illustrated in broken lines.

Referring more particularly to the drawings wherein similar reference characters designate corresponding parts throughout the several views, as illustrated the invention is embodied in an annular cylindrical grid structure or drum designated generally as 10. It will be readily appreciated, however, that the principles and teachings of the invention are not limited merely to the formation of annular grid structures, but rather are also applicable to the construction of grid sructures of other desired configurations, including flat grid structures. Also, it will be understood that, although the nonplanar or waved strip or strip means is illustrated and hereinafter described as connected to a planar strip means, alternatively such waved strip means could be connected to another coil of the same or a second such waved strip.

The illustrated grid structure 10 is closed at its opposite ends by annular, head or end closure plates 12 rigidly mounted on hubs, designated generally as 14, which support stub shafts 16 by which the grid structure 10 is supported and through which it is rotatably driven. The grid structure 10 includes sheet metal, planar and waved (or non-planar) strips 18,20, respectively, which are longitudinally helically wound circumferentially of the grid structure 10 in alternate arrangement and rigidly interconnected at intervals along their lengths. Hence, the grid structure 10 throughout its length includes alternate coils of the strips 18,20, later-' ally adjacent ones of which coils are rigidly interconnected at intervals; and at its ends the grid structure 10 includes coils of the waved strip 20 which are rigidly connected to the end closure plates 12. The strips 18,20 are arranged with their greatest transverse or width-wise dimensions at least generally radially of the grid structure 10 and cooperate to provide the grid structure 10 with a plurality of openings 22 generally radially through the thickness of the grid structure 10. The total open area of the openings 22, as will be understood, may be in the range of to percent of the .circumferential area of the grid structure 10.

The waved strip 20 throughout its length includes alternating diagonal or first segments 24 and connecting or second segments 26, the connecting segments 26 being integral with the diagonal segments 24 and located intermediate and interconnecting longitudinally adjacent ones of the latter. The diagonal segments 24 are at least generally planar and extend across the central plane 28 of the waved strip 20 as they extend longitudinally of the latter, adjacent ones of the connecting segments 26 being on opposite sides of the central plane 28 throughout the length of the waved strip 20.

The connecting segments 26 are of arcuate, generally sharp or pointed configuration to include generally concave inner surfaces 30 and generally convex outer surfaces 32. Each connecting segment 26 hence cooperates with the two adjacent diagonal segments 24 (that is, the diagonal segments 24 at opposite ends thereof) to define a generally V-shaped portion of the strip 20, the connecting segment 26 bounding the at least generally pointed apex (that is, sharp or narrowly rounded apex) of such generally V-shaped portion.

Each of the connecting segments 26, as illustrated, has two sections 34 of its length (that is, sections of its dimension radially of the grid structure substantially laterally enlarged longitudinally of the waved strip to enable insertion of a conventional welding tool 36 internally of the apexes of the generally V- shaped portions, thereby permiting welded interconnection of the connecting segments 26 to the laterally thereadjacent coils of the planar strip 18 and the end closure plates 12. The enlarged sections 34, as illustrated, may be formed with conical inner walls 38 and generaly flat or planar outer walls or bottoms 40 along which they are connected to the laterally thereadjacent structure. The enlarged sections 34, moreover, may be formed by a conventional punch or stamping operation; and the number and location of the enlarged sections 34 on each connecting segment 26 are, of course, variable as required or desired. Hence, the connecting portions 26 may each be provided with only one, or as shown a plurality, of the enlarged sections 34; however, only a minor portion of the length (that is, dimension radially of the grid structure 10) of each connecting portion 26 need be enlarged. I

From the preceeding dscription, it will be seen that the illustrated waved strip 20 throughout its length includes generally V-shaped portions adjacent ones of which have pointed apexes on opposite sides of the central plane 28 of the waved strip 20, and such apexes, being defined by the connecting segments 26 which for minor sections 34 of their lengths are substantially laterally enlarged longitudinally of the strip 20, for minor sections of their lengths are substantially laterally enlarged longitudinally of the strip 20.

It will, moreover, be seen that this beforedescribed construction, due to the provision of the enlarged sec tions 34, provides a non-planar or waved strip 20 of substantially increased buckling strength; and furthermore that a grid structure 10 including such a nonplanar or waved strip 20 possesses significant stiffness and strength while being capable of construction by conventional welding processes. It is believed to be apparent that an annular grid structure 10 employing such a strip 20 may be, as desired or required, used in many applications such as, by way of example, a dryer drum, a filtering drum and/or a supporting drum for use during the manufacture of pulp and paper.

Moreover, although the described grid structure 10 includes a planar strip 18 interconnected with the wave strip 20, it will be seen that such planar strip 18 could be eliminated, in which event adjacent coils of the waved strip 20 could be directly interconnected or, alternatively, connected to laterally adjacent coils of another similar waved strip. A drum including end portions of this latter construction is, for example, described in United States Patent application Ser. No. 289,663 entitled DRUM INCLUDING ANNULAR GRID STRUCTURE filed by Oscar Luthi on same date is believed to be clearly apparent from the beforegoing description.

It will be understood, however, that, although only a single embodiment of the invention has been illustrated and hereinbefore specifically described, the invention is not limited merely to this single embodiment, but rather contemplates other embodiments and variations within the scope of the following claims.

Having thus described my invention, I claim:

1. A grid structure comprising waved strip means including generally V-shaped portion, the substantially pointed apexes of said generally V-shaped portions of said waved strip means comprising sections of greater widths than other sections thereof, and said greater width sections having generally planar bottoms for connection to laterally adjacent structure and being adapted to internally receive a tool for making such connections.

2. A grid structure according to claim 1, wherein adjacent ones of said apexes of said generally V-shaped portions are on opposite sides of the control plane of said waved strip means.

3. A grid structure according to claim 1, wherein said apexes of said generally V-shaped portions extend transversely of said waved strip means.

4. A grid structure according to claim 1, wherein adjacent ones of said apexes of said generally V-shaped portions are on opposite sides of the central plane of said waved strip means, and said apexes extend transversely of said waved strip means.

5. A grid structure according to claim 1, wherein said waved strip means includes first segments and second segements intermediate and interconnecting said first segements, said second segments cooperating with adjacent ones of said first segments to define said generally V-shaped portions, said second segments bounding the generally pointed apexes of said generally V-shaped portions and said second segments having sections laterally enlarged longitudinally of said waved strip means defining said greater width sections of said apexes.

6. A grid structure according to claim 5, wherein said first segments are at least generally planar.

7. A grid structure according to claim 5, wherein said second segments are arcuate.

8. A grid structure according to claim 5, wherein said grid structure is annular.

9. A grid structure according to claim 5, wherein said first segments extend generally diagonally across the central plane of said waved strip means, and adjacent ones of said second segments are on opposite sides of such central plane.

10. A waved strip for use in forming a grid structure, including generally V-shaped portions, the substantially pointed apexes of said generally V-shaped portions comprising sections of greater widths than other sections thereof, and said greater width sections having generally planar bottoms for connection to laterally adjacent structure and being adapted to internally receive a tool for making such connections.

11. A waved strip according to claim 10, wherein adjacent ones of said apexes of said generally V-shaped portions are on opposite sides of the central plane of said waved strip.

12. A waved strip according to claim 10, wherein said apexes of said generally V-shaped portions extend transversely of said waved strip.

13. A waved strip according to claim 10, wherein adjacent ones of said apexes of said generally V-shaped portions are on opposite sides of the central plane of said waved strip, and said apexes extend transversely of said waved strip.

14. A waved strip according to claim 10, comprising first segments and second segments intermediate and interconnecting said first segments, said second segments cooperating with adjacent ones of said first segments to define said generally V-shaped portions of said waved strip, said second segments bounding the generally pointed apexes of said generally V-shaped portions, and said second segments including sections enlarged longitudinally of said waved strip defining said greater width sections of the waved strip.

15. A waved strip according to claim 14, wherein said first segments are at least generally planar.

16. A waved strip according to claim 14, wherein said second segments are arcuate.

17. A waved strip according to claim 14, wherein said first segments extend generally diagonally across the central plane of said waved strip and adjacent ones of said second segments are on opposite sides of said central plane.

18. An annular grid structure comprising circumferentally extending strip means laterally adjacent coils of which are interconnected, said strip means-including a waved strip having alternate generally diagonal segments and therebetween connecting segments interconnecting such said diagonal segments, said connecting segments being alternately on opposite sides of the central plane of said wave strip and said diagonal segments crossing such central plane, said connecting segments cooperating with thereadjacent ones of said diagonal segments to define generally V-shaped portions of said waved strip, said connecting segments bounding the at least generally pointed apexes of said generally V-shaped portions, said connecting segments having sections substantially enlarged longitudinally of the waved strip to cause said apexes of said generally V- shaped portions to include connecting sections substantially enlarged longitudinally of said waved strip, and said enlarged longitudinal sections having generally planar bottoms for connection to laterally adjacent structure and being adapted to internally receive a tool for making such connections.

19. A grid structure according to claim 18, wherein said first segments are at least generally planar.

20. A grid structure according to claim 18, wherein said second segments are arcuate. 

1. A grid structure comprising waved strip means including generally V-shaped portion, the substantially pointed apexes of said generally V-shaped portions of said waved strip means comprising sections of greater widths than other sections thereof, and said greater width sections having generally planar bottoms for connection to laterally adjacent structure and being adapted to internally receive a tool for making such connections.
 2. A grid structure according to claim 1, wherein adjacent ones of said apexes of said generally V-shaped portions are on opposite sides of the control plane of said waved strip means.
 3. A grid structure according to claim 1, wherein said apexes of said generally V-shaped portions extend transversely of said waved strip means.
 4. A grid structure according to claim 1, wherein adjacent ones of said apexes of said generally V-shaped portions are on opposite sides of the central plane of said waved strip means, and said apexes extend transversely of said waved strip means.
 5. A grid structure according to claim 1, wherein said waved strip means includes first segments and second segements intermediate and interconnecting said first segements, said second segments cooperating with adjacent ones of said first segments to define said generally V-shaped portions, said second segments bounding the generally pointed apexes of said generally V-shaped portions and said second segments having sections laterally enlarged longitudinally of said waved strip means defining said greater width sections of said apexes.
 6. A grid structure according to claim 5, wherein said first segments are at least generally planar.
 7. A grid structure according to claim 5, wherein said second segments are arcuate.
 8. A grid structure according to claim 5, wherein said grid structure is annular.
 9. A grid structure according to claim 5, wherein said first segments extend generally diagonally across the central plane of said waved strip means, and adjacent ones of said second segments are on opposite sides of such central plane.
 10. A waved strip for use in forming a grid structure, including generally V-shaped portions, the substantially pointed apexes of said generally V-shaped portions comprising sections of greater widths than other sections thereof, and said greater width sections having generally planar bottoms for connection to laterally adjacent structure and being adapted to internally receive a tool for making such connections.
 11. A waved strip according to claim 10, wherein adjacent ones of said apexes of said generally V-shaped portions are on opposite sides of the central plane of said waved strip.
 12. A waved strip according to claim 10, wherein said apexes of said generally V-shaped portions extend transversely of said waved strip.
 13. A waved strip according to claim 10, wherein adjacent ones of said apexes of said generally V-shaped portions are on opposite sides of the central plane of said waved strip, and said apexes extend transversely of said waved strip.
 14. A waved strip according to claim 10, comprising first segments and second segments intermediate and interconnecting said first segments, said second segments cooperating with adjacent ones of said first segments to define said generally V-shaped portions of said waved strip, said second segments bounding the generally pointed apexes of said generally V-shaped portions, and said second segments including sections enlarged longitudinally of said waved strip defining said greater width sections of the waved strip.
 15. A waved strip according to claim 14, wherein said first segments are at least generally planar.
 16. A waved strip according to claim 14, wherein said second segments are arcuate.
 17. A waved strip according to claim 14, wherein said first segments extend generally diagonally across the central plane of said waved strip and adjacent ones of said second segments are on opposite sides of said central plane.
 18. An anNular grid structure comprising circumferentally extending strip means laterally adjacent coils of which are interconnected, said strip means including a waved strip having alternate generally diagonal segments and therebetween connecting segments interconnecting such said diagonal segments, said connecting segments being alternately on opposite sides of the central plane of said wave strip and said diagonal segments crossing such central plane, said connecting segments cooperating with thereadjacent ones of said diagonal segments to define generally V-shaped portions of said waved strip, said connecting segments bounding the at least generally pointed apexes of said generally V-shaped portions, said connecting segments having sections substantially enlarged longitudinally of the waved strip to cause said apexes of said generally V-shaped portions to include connecting sections substantially enlarged longitudinally of said waved strip, and said enlarged longitudinal sections having generally planar bottoms for connection to laterally adjacent structure and being adapted to internally receive a tool for making such connections.
 19. A grid structure according to claim 18, wherein said first segments are at least generally planar.
 20. A grid structure according to claim 18, wherein said second segments are arcuate. 